Dúvida ao usar o MediaPlayer

public static void playSound(Context c, Som s) {
		MediaPlayer song = null;

		if (s == Som.BUTTON) {
			song = MediaPlayer.create(c, R.raw.button);
		}

		song.setOnCompletionListener(new OnCompletionListener() {

			public void onCompletion(MediaPlayer mp) {
				mp.release();
			}
		});

		song.start();
	}

public void onClick(View v) {
				Util.playSound(getApplicationContext(), Util.Som.BUTTON);
				Intent intent = new Intent(getApplicationContext(),Classe.class);
				startActivity(intent);
			}
		});